Friday, 30 September 2011

Live from Fermilab: Chronicle of a Death Foretold

2:38 pm: It's over. The heart stopped 2:38 pm, the last store number was 9158. Good night.2:37 pm: Helen Edwards all too eagerly pressed the big red button to dump the beam. Soon she will press the big green button to ramp down.2:35 pm:Stop Helen, I'm afraid2:35 pm: The heart is still beating but the brain is dead: Tevatron no longer records the data.2:34 pm: ...though I must say that the CDF show was much more entertaining.2:32 pm: D0 run terminated. They're ramping down.2:29 pm: Somehow the whole ceremony reminds me of this scene.2:28 pm: Time for D0, the better of the 2 Tevatron experiments ;-) Bill Lee from the D0 control room. 2:25 pm: The CDF run has been terminated, 2 million events collected. CDF no longer takes data.2:22 pm: There is now a story of chickenpox children sacrificed at the altar of science. You don't want to know how it ends.2:16 pm: Ben Kilminster live from the CDF control room says that back in 1985 there was only one monitor there. There was also no blogs, Twitter or Facebook. Clearly there is some progress...2:15 pm: Soon the detectors will start shutting down. They don't to watch it...2:10 pm: Tour of the control room. Looks like space movies from the 70s with lots of color lights blinking.2:o4 pm: It started. Booooo. Pier Oddone, the director of Fermilab, speaking. 2:o1 pm: Nothing's happening yet. The stream shows photos of serious faces staring at monitors or parts of the accelerator.1:57 pm: I wonder what will happen to the buffaloes... Will they all be slaughtered and served at the funeral party in the Wilson Hall autrium?1:50 pm: Except for the top quark, is the Tevatron going to be remember for anything? In the coming years their measurement of the top quark and the W boson mass will remain the most precise one - the LHC will have to struggle hard to beat it. Moreover, a number of measurements - especially various production asymmetries - cannot be repeated at the LHC.1:45 pm: The Tevatron will die today but the ghost will linger on a bit longer. Physics analyses based on the full dataset are expected only in about 5 months, for the winter 2012 Moriond conference. After that the trickle will be slowing down, but papers and analyses should will be coming up for several more years. 1:40 pm:Streaming of the execution will begin in about 5 minutes.1:30 pm: Memorial photo of the D0 collaboration in the pit. Not much time left...1:10 pm: Dismantling of the Tevatron will begin in about a week, shutdown, as soon as the superconducting magnets are warmed up to the room temperature. The CDF detector will also be shut down today, while D0 will be operating for 3 more months to get a sample of cosmic events for calibration purposes. I'm not aware of any plans of reusing parts of these detectors for other experiments.12:50 pm: With the shutdown of the Tevatron, Fermilab is losing its dearest child and the place at the forefront of high-energy physics, but for a while it will remain an important laboratory running smaller scale experiments. The dark matter detector COUPP, or the neutrino experiment MINOS will be producing important results that may even make it to blogs ;-) Construction of Mu2e, an interesting experiment to study lepton flavor violation, will begin in 2013. In the long run, however, the future of Fermilab looks bleak. Most likely it will share the fate of other once great US labs, like BNL or SLAC: sliding slowly into insignificance.12:10 pm: One more statistically significant departure from the Standard Model was reported by the Tevatron: the dijet mass bump in W+2j events at CDF. Unfortunately, the effect was not confirmed by D0. It's not clear if this will be sorted out anytime soon...

12:10 pm: The shutdown of the Tevatron should be viewed as a part of the bigger program of shutting down fundamental research in the US. It makes sense: since manufacturing could be outsourced to China, no reason why research could not.12:05 pm: Here you can see the current status of the accelerator. The luminosity is low but the old chap should make it all the way to the end.11:45 am: Wonder how the execution will be carried out? In the state of Illinois they do it as follows:

...Helen Edwards, who was the lead scientist for the construction of the Tevatron in the 1980s, will terminate the final store in the Tevatron by pressing a button that will activate a set of magnets that will steer the beam into the metal target. Edwards will then push a second button to power off the magnets that have been guiding beams through the Tevatron ring for 28 years...

I think there should be 3 people, each pressing a button, only one of which is actually connected to the kicker...11:40 am: It's a beautiful autumn day here in Fermilab today, unusually beautiful. Nature refuses to mourn.11:05 am: The Tevatron has 3-4 more hours to live.11:00 am: Except for the top asymmetry, another Tevatron's measurement returned a result grossly inconsistent with the Standard Model, namely, the dimuon charge asymmetry at D0. Although the interpretation of this result in terms of anomalous CP violation in the B-meson sector has been put to doubt by recent LHCb measurements of related processes, formally the D0 result still stands 10:45 am: The gravestone is ready even before the actual death:

10:15 am: So, Tevatron Run I got the top quark. Run II, which started in 2001, had 2 major goals: find the Higgs and find new physics. From this perspective one must admit that, \begin{evenif} insert here how great job was done \end{evenif}, Run II was a disappointment.9:50 am: Except for the top quark, what were the most important findings of the Tevatron? See the list at Tommaso's blog.9:30am: Tevatron's observation of the anomalous top-antitop forward-backward asymmetry is currently the strongest hint that there may be new physics. The fact it is the strongest is not really encouraging ;-)9:15am: A bit of nostalgia: a page in Particle Data Group from 19969:00am: The LHC is leading the game in most of the Higgs search channels, but for the moment the Tevatron has a far better sensitivity to a light Higgs boson decaying to a pair of b-quarks. Interestingly, they see no excess in this channel (the excess in the combination comes mostly from the H to WW channel), even though they should if the Higgs is there... 8:40am: The eulogies have begun. For the next 2 hours I'll listen to the summary of the most important results obtained by the D0 collaboration.8:30am: They're still accumulating antiprotons; a sort of life support in case the Tevatron trips before the scheduled time. 8:10am: The last store of protons and antiprotons is circulating in the ring since last evening. Current luminosity: 100 ub/sec, more than 3 times below the peak luminosity. Clearly, the Tevatron is already flatlining.8:00am: The Tevatron will go down in history as the place where back in 1995 they discovered the top quark - probably the heaviest elementary particle. 7:50am: Tevatron's first beam was in 1983 so he's dying at 28. One year more than Janis Joplin, Jimmy Hendrix, Jim Morrison, Kurt Cobain and Amy Winehouse. What's similar is that death is coming is when the career is already on the decline. 7:45am: I'm wide awake, it's morning in Fermilab. Putting on my best suit and setting off to the funeral. In less than 7 hours the Tevatron will be no more...

13 comments:

Anonymous
said...

I don't know if you changed the graphics style of your blog to black background/white text in order to "highlight" the death of the Tevatron - but I highly recommend keeping it this way. Readability of the text is much better that in the old style. Keep up the good work.

You're going to hit a nerve saying BNL has slid into insignificance. Maybe for high energy physics (though one can argue for the recent advances in the understanding of QCD from RHIC), but certainly not in general.

A simple perusal of their website shows a large set of research priorities. And though the lab is run by a recovering high energy physicist (and all around great guy), the administration is much more diversified than Fermilab or SLAC. I still find their research capabilities impressive.

If there is no heavier elementary particle, then we can pretty much stop the energy frontier research, given the assumed reductionist approach to high energy physics. More accurate, I would say, is that the top is heaviest known elementary particle (or even in the SM for that matter).

And I take some issue with your comment about the state of BNL. Sure, it's not at the forefront of discovery physics, but there is still a rich accelerator program for the near future in RHIC. The heavy ion side of the project has a versatility that the LHC can't match (although their luminosity kills RHIC), and it's the only polarized proton collider in the world. Hopefully the site of the proposed electron-ion collider as well.

SoLID (Solenoidal Large Intensity Device) will be used in 11GeV PVDIS and SIDIS experiement with different configurations in Jefferson Lab Hall A. The collaboration is exploring the use of the CDF central solenoid. And the BaBar solenoid. And any other SC solenoids of roughly that size they might be able to scrounge.

Paul, with all the people complaining about the "reductionist" approach of modern science (and many have, at length), I have never heard a cogent explanation of what that even means, nor what a sensible alternative would be.

Jester, claiming the top as "the heaviest elementary particle", that sounds rather bold, considering that all you need is some funny scalar field floating around with a steep potential, like flavons, and there you go. Or the righthanded Neutrinos, if they exist. We can very soon say with good confidence that the top is the heaviest fermion that is chiral under the standard model gauge group. Any Statement beyond that seems completely without justification to me.

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Résonaances is a particle physics blog from Paris. It's about the latest news and gossips in particle physics and astrophysics. The posts are often spiced with sarcasm, irony, and a sick sense of humor. The goal is to make you laugh; if it makes you think too, that's entirely on your own responsibility...